This section is from "The Horticulturist, And Journal Of Rural Art And Rural Taste", by P. Barry, A. J. Downing, J. Jay Smith, Peter B. Mead, F. W. Woodward, Henry T. Williams. Also available from Amazon: Horticulturist and Journal of Rural Art and Rural Taste.
In the March number of the Horticulturist, for 1858, I described a system of building glass-houses on the fixed-roof, or continuous-rafter principle. Having, since then, had several houses put up on a different method, and one which is in some respects superior to that already described, I have prepared the following sketches of construction for the benefit of those who are contemplating building. For Orchard houses or, indeed, any kind of structure for plants, I consider that it will form the most elligible combination of advantages.
Fig. 1, shows a portion of the front elevation; - a a are 8 by 6 inch rafters which are the main roof supports; these are tied together as shown by the cross-piece h in fig. 4. They are set 7 1/2 feet apart, and are rebated on the edges to form a glass-bed; b b b are cross-pieces made of inch plank 3 inches wide, inserted between the rafters, so that their upper edge will be one and a half inches below the upper edge of heavy rafter. These support the sash bars f, of which a full-sized section is shown at fig. 3; d is an inch board 14 inches wide, let 1 1/2 inch into the rafters so that it is flush with the glass-bed, projecting so as to form an eave to throw of water. The sash bars butt against this board, and the glass laps over it, forming and neat a tight finish. In glazing the glass is merely bedded in putty, - none used outside; e shows how the ventilators are situated, - they are hinged at top, and worked from the inside by an upright rod; the upright elevation is constructed in a similar manner as the roof, and portions of it may be hinged to the wall plant for ventilators.
Fig 2 is a section across b, c in fig. 1.
The letters in the figures have reference to the same parts in all. Fig. 4 is a section of a grapery built on this system, showing the walls, border, etc. The dimensions of this house are, width 28 feet, and 15 feet in height from level of sill. The stone walls ii are 6 feet in height; 2 feet above the outside ground level, and 4 feet foundation. The centre posts are set upon piers; in houses of less width, these centre supports maybe dispensed with, if the upright corner posts are well braced to the sill.
Fig. 4 is introduced more with a view to show the peculiarity of treatment both of the border and plants, than as illustrative of the construction of the house. N is the outside ground level; k, a stratum of coarse material for drainage: m the undisturbed subsoil, and b the prepared border. The soil in this border was taken from a corn-field and a considerable portion of sand mixed with it, so as to render it perfectly pervious to water. No manure of any kind was used in its formation, all necessary stimulants being applied in a liquid state when found requisite. The plants so far have made very satisfactory progress, - not so strong and luxuriant growths as are sometimes produced in rich borders, but sufficiently vigorous to perfect good crops. Borders made up with a large portion of decomposable material, excite a luxuriant growth which is seldom maintained for any considerable number of years; the organic matter in the soil decays and its texture becomes sodden and compact. A border made as described above will always present a suitable medium for the ramification of roots; and as already remarked, stimulants can be applied at any time when the plants most require it Borders. - It will be perceived that there is no outside border.
One of the greatest difficulties in the management of vines under glass, when the roots are is outside borders, is their tendency to prolonged growth in the fall. The heavy autumn rains on the soil, combined with the warm, growing temperature in the house, prevents the thorough maturation of the shoots, and they remain in active growth until suddenly denuded of foliage by frost. Various precautions are adopted to guard against this evil, such as covering with leaves, manure, and occasionally with glazed sash, or boards. I have obviated all this by having no outside borders, so that the roots are as completely under control as if the plants were in pots. . It may be surmised that such a small portion of soil would rapidly become exhausted, and unable to support a crop; but when we consider the heavy crops that are produced in pots we need have no fear on that score. I am convinced that extensive rich borders are not only unnecessary, but absolutely injurious so long as we do not provide for a corresponding extension of the branches.
In the limited extent of a rafter in a grapery, the plants, at least after the first season's growth, are continuously subjected to a severe pinching process in order to keep anything like regularity.
A proportionate amount of foliage is indispensable to the ripening of a crop, and where there is not sufficient space to grow it, we must expect red grapes when they ought to be black.
Among the many reasons given for the non-coloring of grapes, the want of foliage has never been considered as a cause. We are very apt, in our attempts, to discover causes, to ignore anything likely to interfere with our routine practice, or infringe upon a favorite system. How often has it been advanced that it is fatal to allow grape-vines to bear any fruit the second year from planting, even although the plants are strong enough to warrant the ripening of a few branches; and, in cases where it has been allowed, subsequent failures have been attributed to that circumstance. Experience convinces me that the fruit produced on such occasions will invariably be found of the very best quality, fully flavored and matured; and this not so much on account of supposed superior management, but from the fact, that in order to fill up space, a certain freedom of growth is allowed, furnishing a sufficient amount of foliage to thoroughly mature the crop. But when once these same plants have filled their allotted space, and no room for further extension is provided, the pruning and cutting that they have to be subjected to during growth, diminishes the foliage to such an extent that they cannot perfect an average crop; and instead of attributing the failure to its proper source, the fact of failure will be held up as illustrative of the evil effects of early cropping, with which, it indeed, has not the most remote connection.
Mr. Saunders' very correct idea, that an abundance of foliage is necessary to the proper ripening of grapes, if not very new, is quite ignored by many grape-growers, but is, in my opinion, one of the fundamental principles of the science. In my own vinery, the abundance of foliage has excited remark, as compared with the murder-lous system of close catting practised by some cultivators.
I don't quite approve of Mr. Saunders' plan of renewing the whole plant annually, which appears to be rather too severe treatment, and must, I should think, eventually enfeeble the plant to an injurious extent.